520 
PODOCARPUS 
characters). 40 sp. E. As. and S. temp, and trop. Dioecious. The 
? has a peculiar structure. There are usually three pairs of scales, 
decussate. One of the middle pair projects above all the rest, bear- 
ing an anatropous ovule. The other 5 are sometimes united to form 
the so-called receptacle. The fruit usually consists of a fleshy mass 
(the ‘receptacle’) bearing an arillate seed. In some sp. the sterile 
scales do not become fleshy. The timber is valuable. 
Podochilus Blume. Orchidaceae (ro). 12 sp. Indo-mal. Epiphytes. 
Podolepis Labill. Compositae (iv). 13 sp. Austr. 
Podophyllum Linn. Berberidaceae. 5 sp. N. temp. In P. peltatum L. 
the rhizome sends up yearly a shoot bearing two large peltate leaves, 
which hang down in the young condition like a closed umbrella. 
A drug is prepared from the rhizome. Fruit a berry, whose flesh 
consists chiefly of the placenta which grows up round the seeds 
(wrongly termed an aril). 
Podostemaceae. Dicotyledons (Archichl. Rosales). 22 gen. with 100 
sp. trop. A remarkable order of plants (p. 163) adapted to life in 
rushing (i.e. also generally rising and falling) water; they grow on 
rocks in rivers and are very local in distribution, contrary to the usual 
rule in water-plants. The morphology of the vegetative organs is 
extremely varied and complex. The seeds are shed on the rocks 
during the drier season of the year, and germinate when the rains 
cause them to be submerged. The primary axis is usually small, and 
from the base there buds out a green thallus , usually of adventitious 
root nature (pp. 30, 39). In Tristicha, Podostemon, &c. it is =*= fila- 
mentous, creeping on the rock, and attached to it by hairs or exogenous 
projections termed haptera. In Dicraea it is ± freely swimming and 
often ribbon-like or sea- weed-like. In Hydrobryum it is ± flattened, 
creeping, lichen-like. In Lawia there is a flat creeping thallus of 
shoot nature, and other complications occur in Castelnavia and others. 
From the thallus in most cases endogenous secondary shoots arise, 
and remain vegetative (leaves alt., simple or much divided) till 
the latter part of the rainy season, when they form firs, which open 
when exposed by the fall of the water. The plants die after shedding 
their seed, unless an early rise of water occurs. Their outer tissues 
are usually very siliceous. Firs, simple, $ (dioecious in Hydro- 
stachys, which is better placed in a separate order), regular or not, 
hypogynous; P3-5 or 00, or (3-5), Ai-2-00, G usually (2) 
2-loc. with thick axile placenta. The more dorsiventral the vege- 
tative organs, the more dorsiventral in general is the flr., the 
phenomenon showing progressively in perianth, androeceum, gynoe- 
ceum, fruit, seed, and embryo. Ovules 00 (exc. Farmeria), anatropous. 
Capsule; exalbuminous seeds. Chief genera ; Tristicha, Lawia, 
Rhyncholacis, Mourera, Podostemon, Dicraea, Hydrobryum, Cas 
telnavia. Placed in Multiovulatae Aquaticae by Benth. -Hooker, 
Saxifraginae by Warming. [For full details see Willis in Ann. Perad. 
I, 1902 and literature there quoted.] 
